No, it’s not a trendy new way to barbecue pork. Nor is this some hot dance craze, getting a gazillion hits on YouTube.

The Chelsea chop is a way of pruning flowering perennials so that they grow and look better. And, surprisingly, it works like a charm.

The technique gets its name from the Chelsea Flower Show, because gardeners in the U.K. do this around the end of May, when their famous floral fest is on.

Yet here in Ontario, I find it’s best to brandish my shears around the end of June, since our plants take longer to get established. The outcome is gratifying: more side shoots, bushier growth, less flopping, and — big plus — more flowers.

How to perform the Chelsea chop? Just cut back by about half any tall perennials which produce their flowers later in the summer. Yes, a half, folks. And sure, it does take courage. When the plants are barrelling along nicely, you can’t help thinking: Should I be lopping their tops off like this? Am I nuts? Will I wind up having no flowers at all?

But trust me. In previous summers, I’ve Chelsea chopped my black-eyed Susans (Rudbeckias), sunchokes (Helianthus), sneezeweed (Heleniums) and purple cone flowers (Echinacea). And far from throwing hissy fits, they reacted favourably. Their flowers tend to come along later and may be smaller than usual. But you get more of them and the plants don’t flop over and look messy.

With a big clump, you can also stagger the pruning — that is, leave the plants at the back to grow to their full size, yet trim the ones in front so they’ll all wind up forming an attractive display.

This drastic-sounding manoeuvre also works with phlox. And this year, I’m taking the choppers to my Sedum Autumn Joy — a plant that I confess to having a love-hate relationship with. While its fleshy leaves hide decaying bulb and perennial poppy foliage effectively, yikes, how hideous those huge bilious pink “broccoli” flower heads can look in August. And the whole plant careens over like a drunken sailor. So if the Chelsea chop makes my Sedum behave more decorously, bring it on.

A few other pointers: Don’t chop early flowering perennials like lupines — or you will get no blooms. Make sure the garden shears are sharp, so you make clean cuts. And don’t worry about positioning the shears at a point on the stems where they’re about to branch. This is important when pruning shrubs, but with tough-as-old-boots flowers like Rudbeckias, it doesn’t matter a hoot.

And here’s a curious bit of trivia about the Chelsea chop. Although the Brits claim ownership of this novel “off with their heads” approach to pruning perennials, the idea actually originated with an Ohio gardener called Tracy DiSabato-Aust. Go figure. You can learn more about her — and her bestselling garden books — at www.tracylive.com

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